Primarily for Crusader though the original would be handy too; how do you balance wheat farms, mills and bakeries?
Distance appears to be a factor in this, I think.
On average it seems like:
1 Wheat Farm, 1 Mill, 5-6 Bakeries.
But I am not quite sure on this. Also, if anyone knows, how do you compare output from a wheat chain to say, an orchard? I have 9 granaries full of bread and one with a couple units of cheese or apples, and I think it could afford a little bit more balance.

distance is generaly more important from the farm to the stockpile - you should be able to place the mill, granery and bakeries next or very near to the stockpile on most maps.
As for farms, I use them as my main source of food income - generally 2 will work for most maps unless there is a very big distance from them to the stockpile then 3 or 4 are needed.
One mill can support at least 7-8 bakeries though two can deal with larger incomes of grain quicker *good early on when you might have lower food reserves and need faster processing)
If you have enough flour from your one mill you can run even more bakeries off it - I do in crusaders though the balance for this bit might be a little different for the original
Cheese, apples and meat are good bonuses, but apple farms are large to place and don't generate as longer lasting food as grain - its good for setting to a not eat option and build up stores for when you might need extra favour from your people (say you run out of beer but still need taxes!) and also if you get attacked and have your farms destroyed.
Cheese is good early on and I tend to build 2-3 if I can at the start for early instant food - but later on the cows are used for leather and catapults ;)